Configuration
4.12 Data point configuration
CP 1243-7 LTE
88
Operating Instructions, 04/2017, C79000-G8976-C381-03
Table 4- 2
Bit assignment of status byte 0
Bit
7
6
5
4
3
2
1
0
Flag name
-
NON_
EXISTENT
SB
LOCAL_
FORCED
CARRY
OVER_
RANGE
RESTART
ONLINE
Meaning
-
Data point
does not
exist or S7
address
unreachable
Substitute
value
(Bit is not
set.)
Counted
value over-
flow before
reading the
value
Limit value
of the ana-
log value
prepro-
cessing
overshot /
undershot
Value not
updated
after start
Value is
valid, CPU
in RUN
Bit status
(always
0)
1
1
(irrelevant)
1
1
1
1
Generation of events if a data point status changes
With data points that were configured as an event, the change to the status bit of the status
identifiers described below also leads to an event being generated.
Example: If the value of the status "RESTART" of a data point configured as an event
changes form 1 (value not yet updated) to 0 (value updated) when the station starts up, this
causes an event to be generated.
4.12.6
Data point index
Configuration of the data point index
Within a CP, the indexes of the data point classes must comply with the following rules:
●
Input
The index of a data point of the type input must be unique throughout all data point types
(digital inputs, analog inputs etc.).
●
Output
–
A data point of the type output can have the same index as a data point of the type
input.
–
Several data points of the type output can have the same index.
Note
Data points for the inter-station communication with a CP in another S7 station
Note that for inter-station communication, the indexes of the two corresponding data points
(data point pair) must be identical for the sending and receiving CP, see also section Partner
stations: Configuring the inter-station communication (Page 99).
